Query about Question 5 from "PrepSwift: # of Numbers in Factorials II" [12368]

Link: https://prepswift.gregmat.com/quizzes/quiz/of-numbers-in-factorials-ii-quiz (Question 5)


I don’t understand the solution at all. Can someone explain this please

This question is equivalent to finding the number of primes that are factors of 36! . Maybe that provides you with a nudge in the right direction.